There are a number of dispensers known in the art for dispensing and cutting sheets of paper toweling or other similar materials. These dispensers are generally divided into two types of dispensers. The first type is a dispenser which the user needs to physically contact the dispenser to dispense a sheet of the material from the dispenser. The second type of dispenser is a “sanitary” or “no-touch” dispenser. “Sanitary” or “no-touch” dispensers allow a user to obtain a sheet of the web material by only touching the web material extending from the dispenser or by activating an electronic sensor to advance the sheet material. There is no need for a user to touch any part of the dispenser in order to obtain a sheet from the dispenser.
Currently available sanitary or no-touch dispensers are operated either manually or electronically. In manual sanitary or no-touch dispensers, the process of dispensing and cutting the web material is carried out automatically by a user pulling on the free “tail” end of the web material that extends from a dispensing slot in the dispenser. In a typical configuration, the web material is engaged against a rough friction-enhancing surface of a feed drum and the action of pulling the web tail causes the drum to rotate. The drum often includes a drive mechanism and, after the initial pull on the web tail by a user, the drum is driven a predetermined rotational degree to dispense a metered amount of the web material, which is often called a “sheet”. A cam driven cutting mechanism may be provided in the rotating drum that pivots out of a slot in the drum to automatically cut the web at the proper length. This type of dispenser typically includes a stored energy mechanism, such as an eccentric cam, that is spring loaded during the initial rotation of the feed drum. This mechanism generally provides energy to aid in cutting the sheet material from the web and causes the drum to continue to rotate after the web has been cut to form the sheet. This action causes an additional length of the web material to be fed out of the dispensing slot as the tail for the next dispensing sequence. As a result, the user only touches the tail end of the web material during dispensing of a sheet of the web material.
Although effective, the conventional manual or mechanical sanitary dispensers utilizing automatic mechanical cutting and feeding mechanisms can be relatively difficult for some users, such as young children and elderly adults, to use. For some users, these manual or mechanical dispensers present an inordinate amount of resistance to pulling a sheet of the web material from the dispenser. This may be particularly true when the initial pulling action by the user also provides the force needed to load the potential energy spring of the automatic tail feeding mechanism. Further, the high resistance to pulling created by loading of the potential energy in the spring mechanism also means it is necessary for the web materials being dispensed from the dispensers to have a relatively high tensile strength. If the tensile strength of the web material is too low, the web will tend to tear during dispensing, which may cause the dispenser to jam. As a result, the next user will not be able to use the dispenser in a hands free mode to retrieve a sheet of the web material from the dispenser. Additionally, the torn pieces, or tabs, of the sheet material are often dropped on the floor presenting an undesired and unsightly mess on the washroom floor. Lower tensile products are desirable as they are generally softer and are more absorbent than higher tensile products.
Advances have been made in the art relating to purely electronic sanitary web material dispensers. With such dispensers, the unit is typically activated upon detection of motion of a user's arm or hand. A motor is subsequently energized through a control circuit and power source to drive a feed roll and thus dispense a measured length of the web material. The user then grabs the exposed web material and pulls the web material at some angle to the dispenser cover causing a sheet of material to be separated on a cutting edge or serrated tear bar. The cycle is repeated for the next user.
A significant drawback with electronic sanitary dispensers is that electrical power is consumed by the motor to drive the full length of towel material from the dispenser. In addition, these dispensers require a relatively high energy use to overcome the inertia of the roll of web material at rest. That is, the relatively heavy roll of the web material takes a large amount of energy to start the motion of the roll of the web material so that a length of the web is advanced in the dispenser. Dispensers having a sensor to detect motion of a user's hands or arms also require that the sensor be powered with electrical power, which creates a constant drain of the power supply. In these electronic dispensers for web materials, battery life is greatly reduced due to the high energy demands to advance the roll material and the constant drain on the battery to operate the sensor, which results in frequent battery replacement and maintenance. Other drawbacks of the electrical systems with sensors include false triggers which causes the web material to be dispensed from the dispenser unintentionally. In addition, many electronic dispensers also lack of an emergency feed when the batteries are too weak to activate the motor.
There is a need in the art for a sanitary or no-touch web material dispenser which overcomes the problems of the manual and electrical sanitary or no-touch dispensers noted above.